The present invention proposes an apparatus which comprises a communication module configured for communication in a carrier aggregation mode aggregating a primary and at least one secondary carrier, a measurement module, and a control module, configured to retrieve measurement information pertaining to a measurement to be conducted of at least one secondary carrier associated to the primary carrier in the carrier aggregation mode, and instruct the measurement module to conduct a measurement of the at least one secondary carrier based on the measurement information, determine, based on a measurement result, an extent to which the measured secondary carrier is usable for transmission. Also, a corresponding method and computer program product is proposed.